The present invention relates generally to ultrasonic detection systems, and in particular to the field of biological detection using ultrasonic frequencies.
Ultrasonic frequencies have been used in a number of prior art systems for the detection of material density interfaces in fluid bodies. Ultrasonic devices operate on the theory that material interfaces can be detected by the reflection of sonic or ultrasonic frequencies. An ultrasound device will emit a burst of energy at a specific frequency and then monitor the fluid body for echoes reflected off the density interfaces. The distance at which the reflected surface is located from the ultrasound device can be calculated by the velocity of the emitted frequency through the fluid multiplied by the time between the energy burst and the reception of the reflected echo. These echo patterns can also be analyzed to determine attributes of the reflecting body such as its density by observing the energy strength of the reflected echo.
The concept of ultrasonic detection has been used with success in several areas of the medical industry. Ultrasonic transducers and detectors placed on the skin of a patient can provide valuable data on the functioning and location of internal organs of the body through non-invasive means. Ultrasonic detection in the monitoring of human pregnancies, for instance, has proven to be a safe and effective medical tool that allows a doctor to check on the progress of a fetus without the use of harmful radiation as in X-rays.
Another use of ultrasonic detection means has been in the field of animal husbandry. Ultrasonic detectors have been used as valuable tools both in the field of veterinary science and animal breeding. Very accurate information on the health and progress of farm animals can be determined from telltale ultrasonic reflection signatures which are common among animals of common breeds. For example, ultrasonic pulsing and detection has been used for detecting pregnancies in farm animals, since the buildup of amniotic fluid in the enlarged uterus of a pregnant farm animal provides a very distinct echo pattern.
Another use of ultrasonic detectors in the field of animal husbandry has been the calculation of the amount of backfat on hogs. The calculation of the distance between reflected echoes has been used to distinguish between various layers of tissue and fat for the grading of hogs. This alternative ultrasonic grading technique has been widely adopted due to the more humane treatment of animals by using non-invasive techniques to check the quality of the hogs.
Prior art ultrasonic detectors, whether used for checking for animal pregnancy or for checking depth of backfat, have used various indicator techniques to alert the operator of the presence or absence of the sought quality in the animal. Visual and audible indicators that have been used include alert buzzers, cathode ray tube displays and digital numeric readouts. These various ultrasonic detector devices have all suffered from common problems due to the harsh operating conditions of the environment in which they are used. Erroneous readings may result from the misuse or mishandling of the ultrasonic devices which leads to a breakdown in the confidence of their operation. Such problems include the poor contact of the ultrasound transducer to the body of the animal, the failure of internal electronic components of the ultrasound circuits, and the use of partially exhausted batteries within the circuits.
The present invention overcomes the shortcomings of these prior art ultrasound detection devices by providing for power-on confidence testing of the entire circuit to check out the individual circuit components and verify the correct functioning with an audible tone. The present invention also continuously monitors the skin contact between the ultrasound transducer and the skin of the animal being monitored. The present invention also includes a continuous battery check to indicate when the battery falls below an acceptable operating threshold voltage.